a. Field of the Invention
The invention relates generally to nut harvesters for collecting nuts directly from the ground and thereafter separating unwanted trash such as leaves, twigs, grass, and fine dirt from the harvested crop.
More specifically, the invention is directed towards a harvester including a more rapid and efficient air flow separator for segregation of the crop from intermixed orchard debris.
b. Description of the Prior Art
The modern nut harvester performs the dual job first of collecting the windrows of nuts and intermixed debris, and then separating the nut units from the debris for immediate return of the latter to the orchard floor. Harvester pick up mechanisms have been improved to the point where efficient windrow collection can be performed at relatively high harvester speeds. However, previous nut and trash separation systems have often proved unable to keep pace with collection mechanism at these higher speeds. As a consequence, the nut and trash separation step continued to be the "bottleneck" of the overall harvesting process.
Nut and trash separation mechanisms which utilize an air flow passing transversely through a perforated conveyor, uplifting and removing the lighter and more aerodynamically responsive trash material, are well known in the art. The conventional scheme calls for a centrifugal fan sufficiently powerful to create a vertical flow passing through a portion of the foraminous conveyor. The trash, carried upwardly from the conveyor and eventually discharged upon the ground, is thereby separated from the relatively heavy nut units. While this approach has worked fairly well, the conveyor must be run slowly to ensure that all of the debris is removed. If the air flow rate is increased in an effort to speed the separation process, a considerable number of nuts will be carried away with the debris and lost through the harvester's waste discharge.